holonomic propulsion

AKA Killough platform

Holonomic drive is a concept where, no matter what the orientation of the vehicle, and no matter what its current trajectory, you can simply say, "go this way, this fast" and the drive mechanism will accommodate that request. No turning should be required to do this - reorienting the vehicle to go a particular way is cheating.

TRIANGULAR solutions are awesome for this. Omniwheels, or at least wheels which have rotational traction but easily slip side-to-side, are also important parts of a holonic drive solution.

It's possible to drive a holonomic platform with only two inputs: (a) what direction (b) how fast.

With some pretty straightforward trigonometry, you can convert those two inputs into power levels for three drive motors.